Optical properties of gold-silica-gold multilayer nanoshells
Optical properties of gold-silica-gold multilayer nanoshells
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DOI：
10.1364/oe.16.019579
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发表时间：
2008-11-24
期刊：
影响因子：
3.8
通讯作者：
Drezek, Rebekah A.
中科院分区：
文献类型：
--
作者：
Hu, Ying;Fleming, Ryan C.;Drezek, Rebekah A.
利用同心多层球的Mie理论研究了金-硅-金多层纳米壳的光谱和角辐射特性。利用等离子体杂化模型和普适标度原理解释了多层纳米壳的光谱可调谐性。较薄的中间二氧化硅层，按粒度缩放，使等离子体共振红移。这种偏移对整体粒度相对不敏感，并且遵循相对于常规二氧化硅-金核-壳纳米壳的共振波长的通用缩放原理。由内核提供的额外的可调谐性进一步将消光峰转移到更长的波长，这在常规的亚100 nm纳米壳上难以实现，这是由于合成纳米金涂层的限制。我们发现多层纳米壳具有更大的金核、更薄的二氧化硅层和更薄的金外壳，吸收力更强。散射强度和角辐射图案被发现不同于传统的纳米壳由于从内核的光谱调制。多层纳米壳可以在二氧化硅-金核-壳纳米壳主要前向散射的波长下提供更多的后向散射。(C)2008年美国光学学会
The spectral and angular radiation properties of gold-silica-gold multilayer nanoshells are investigated using Mie theory for concentric multilayer spheres. The spectral tunability of multilayer nanoshells is explained and characterized by a plasmon hybridization model and a universal scaling principle. A thinner intermediate silica layer, scaled by particle size, red shifts the plasmon resonance. This shift is relatively insensitive to the overall particle size and follows the universal scaling principle with respect to the resonant wavelength of a conventional silica-gold core-shell nanoshell. The extra tunability provided by the inner core further shifts the extinction peak to longer wavelengths, which is difficult to achieve on conventional sub-100 nm nanoshells due to limitations in synthesizing ultrathin gold coatings. We found multilayer nanoshells to be more absorbing with a larger gold core, a thinner silica layer, and a thinner outer gold shell. Both scattering intensity and angular radiation pattern were found to differ from conventional nanoshells due to spectral modulation from the inner core. Multilayer nanoshells may provide more backscattering at wavelengths where silica-gold core-shell nanoshells predominantly forward scatter. (C) 2008 Optical Society of America